1. Technical Field
The invention relates to a line head for focusing lights emitted from luminous elements on an imaging surface by microlenses.
2. Related Art
The following technology for the purpose of aligning the positions of microlenses and luminous elements is disclosed in JP-A-9-52385 and JP-A-10-16295. In the related art disclosed in these patent literatures, light quantities of light beams emitted from the luminous elements are measured via the microlenses. The positional relationship of the microlenses and the luminous elements is determined such that a measurement result exhibits a specified light quantity distribution. The microlenses disclosed in JP-A-9-52385 and JP-A-10-16295 are a rod lens array in which rod lenses with a refractive index distribution are arranged in an offset manner and have an optical property of erecting and unity-magnification.